Improvement in piano-fortes



UNITED Sterns Farmer @Errea DAVID DECKER, OF NE\V YORK, N. Y.

IMPROVEMENT lN PlANG-FGRTES.

Specification forming part of Letters Patent No. ih, dated January l0,186.3.

T 0 @ZZ whom, it may concern:

Be it known that I, DAvin DECKER, of No. 91 Beecker street, of the city,county, and State of New York, have invented a new and usefulImprovement in Agraffs for Piano- Fortes; and I do hereby declare thatthe following is a full, clear, and eXact description of the same,reference being had to the accompanying drawings, forming part of thisspeciiication.

In all grand and in some square piano-fortes what are known as agraffs7are used to connect the strings with the wrest-plank; but it hashitherto been found impracticable in the square instrument and difficultin the grand to apply them in the treble portion of the scale withoutscrewing them into the iron plate, which is objectionable on account ofits giving the strings a hard and impure tone. The difficulty inapplying them in the treble portion of the scale has arisen from the eX-treme shortness of the strings,-the shortest being but one and seveneighths-inches, and the center of the hammer requiring to strike thestrings at a distance from the wrest-plank bearing equal to fromone-sixteenth to oneeighteenth part of the whole length of that portionof the string between its two bearings. With an agraff of the old kindthe hammer working as close as possible to the wrest-plank withouttouching it would have required the screw of the agraff to be screwedinto the wrest-plank at the extreme edge of the latter, and the screwcould not have had the requisite hold in the wood, and therefore theagraff was never used in the treble except when screwed into the ironplate. The object of my invention has been to obtain some means ofemploying the agraff screwed directly into the wood of the wrest-plank,and my improve ment in the agraff consists in a simple change in itsconstruction by which that much-desired end is accomplished.

To enable others skilled in the art to make and apply my invention, lwill proceed to describe it with reference to the drawings.

Figure lis a side view of an agraff as heretofore constructed. Fig. 2 isa side view of my improved agraff. Fig. 3 is a transverse verticalsection of the wrest-plank, showing the only manner in which the agraff,as heretofore constructed, could have been applied in the dottedoutline,) for the passage of the string` through it, the head c beingdirectly over the center of the `screw and its iiattened sides notprojecting over or beyond imaginary lines drawn lengthwise of the screwalong the tops of the threads thereof.

My improved agraffs (shown in Figs. 2 and 4) only differ in constructionfrom the former in having the heads c so constructed as to projectbeyond the imaginary line aforesaid, or, in other words, to overlap thescrew on that side which is toward the hammer, as illustrated in Fig. 4.Now, in inserting the first-described agraff directly into the woodenwrest-plank, that face of the head c which is toward the outer edge ofthe wrest-plank cannot be brought flush with the face of the plank or bemade to project slightly over or beyond the said face, as is desirable,so that the hammer may work as close to it as is necessary to strike thestring at the proper point without inserting the screw a so close to theedge of the plank that the tops of its threads will be close to orproject slightly beyond the face of the plank, as shown in Fig. 3, thusleaving the screw unsupported on that side; but by constructing the headto project beyond the line of the tops of the threads or overlap thescrew, as shown in Figs. 2 and 4, the screw can be inserted into thewrcst-plank so far from the edge or face thereof as to inclose itentirely within the wrestplank and leave a thickness of wood on itsouter side beyond the tops of the threads, as shown at e in Fig. 4,thu-s giving it the necessary support. This result, though obtained bysuch very simple means, has never before been accomplished.

Vhen the agraff has been screwed into the plank, its collar Z is filedoff flush, or nearly so,

with the face of the head which is toward the hammer, to enable thelatter to pass by it and reach the string.

My improved agraft is not limited in its application to the treble partof the instrument, nor to a square piano-forte, but it is in the trebleportion of the scale that its application is of the greatest importance,as it produces in the strings of that portion of the scale of theinstrument a purity of tone never before obtained.

What I claim as my invention, and desire to secure by Letters Patent,is-

'The construction of the agrail used in piano fortes, substantially asherein described, whereby the face of its head Which is toward thehammers may be ilush with or project slightly beyond the edge or face ofthe Wrestplank while its screw is entirely inclosed in the Wood of thesaid plank and a sufficient supporting thickness of Wood is left on theouter side of it to obviate the necessity of screwing it into the ironplate.

DAVID DECKER.

Witnesses HENRY T. BROWN, J. W. CooMBs.

